lubuntu@lubuntu:~$ e2fsck -b 32768 /dev/sda
e2fsck 1.42.10 (18-May-2014)
e2fsck: Permission denied while trying to open /dev/sda
You must have r/w access to the filesystem or be root
lubuntu@lubuntu:~$ sudo e2fsck -b 32768 /dev/sda
e2fsck 1.42.10 (18-May-2014)
e2fsck: Bad magic number in super-block while trying to open /dev/sda

The superblock could not be read or does not describe a valid ext2/ext3/ext4
filesystem.  If the device is valid and it really contains an ext2/ext3/ext4
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
    e2fsck -b 8193 <device>
 or
    e2fsck -b 32768 <device>

lubuntu@lubuntu:~$